Improvement in sewing-machines



Y 2 Sheets-Sheet 1. J. P. EMSWILER.

Sewing Machine.

No. 25,002. Patented Aug. 9, 1859.

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2 Sheets-Sheet 2. l. P. ENISWILER.

, Sewing Machine.

No. 25,002. Patented Aug. 9, 1859. y

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J. P. EMSVILER, OF KNIGHTSTOVN, INDIANA..

IMPROVEMENT IN SEWING-MACHINES.

lpectieaton forming part of Letters Patent No. 25,002, dated Angus' S, 1659.

To all whom t may concern:

Be it known that I, J. P. EMswi'LnR, of Knightstown, Henry county, and State of Indiana, have invented certain new and useful Improvements in Sewing-Machines, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming part of this specification, in which- Figure l represents a front elevation of a sewing-machine embracing my improvements. Fig. 2 represents a side view of the same. Fig. 3 represents a plan of the table. Fig. 4 represents a longitudinal section of the shuttle and'bobbin. Fig. 5 represents a front view of the shuttle, showing the interior of the same.

The object of my improvements in sewingmachines is to adapt the machine for sewing materials varying greatly in thickness without changing the position orthe movement of the feeding mechanism, as heretofore; and my invention for4 effecting this object consists in the application of a plate arranged upon a guide so that it can be slid forward under the needle and the pressure-pad, and thus raise the bed in relation to the feeding mechanism at this point and adapt the machine to sew materials varying in thickness 5 and it also consists'in the application of a longitudinal spring in the bottom of the shuttle-box, arranged to bear on the surface of the thread on the bobbin when nearly full and on the heads of the bobbin when the thread is partially drawn off, by which means the tension required to draw the thread from different parts of the bobbin is equalized and a more uniform and regular interlocking of theupper with the lower thread is produced.

In the accompanying drawings is repre sented a sewing-machine embracing my iniprovements, which consists of a table or stand, A, on which the material to be sewed rests, and which also supports the moving and stationary parts of the machine. A main driving-shaft, B, with its bearings in ears under the table, has attached to it two open-grooved cams, C and D. The one, O, gives motion to the needle, and the other, D, to the shuttle, and these two cams are so constructed that during one revolution they communicate three vibrations to the needle and shuttle. The connection between the cams and the needlebar and shuttle-driver are made in the manner,

well known in sewingmachines, and therefore do not require particular description. The arm E, driving the needle-bar F, is pivoted to a bracket, G, extending upward from the rear of the table, and passes through the needle bar. An eye, a, is made inV the outer end to form a guide Ior the needle-thread, and attached to the arm is a tensionspring, b, for the needle-thread, which passes around in front ofhthe needle-bar. In the guide H of the needle-bar holes c are made, through which the needle-thread passes. The needle-thread in passing from the spool is carried through an eye, d, in the top ofthe needle-bar, thence v through the eye a on the needle-bar and through one ofthe holes inthe needle-bar guide, depending upon the amount of thread taken up by the material in forming each stitch, thence around the spring b, and again through the eye ato the eye of the needle. As the needle ascends the spring b and eye a, aroundA and through which the thread passes, are car ried above the holes c inthe needle-bar guide,

.and the amount of thread drawn off from the spool is equal to the distance from the hole c to the eye a and the spring b. This amount may be either increased or diminished, as re quired for the stitches in materials varying in thickness, by changing the thread from one hole to another in the needleguide. The slack.

of the thread between vthe needle and fabric sewed is taken up and the stitch drawn tight by means of the spring b, as in other sewingmachines. VA forked bracket, I, is attached to the needle-arm E, and carries the spool K, supplying the thread to the needle. A metalA lic rod or wire, e, pointed at both ends, is

passed through the hole in the spool, and one,

point ofthe rod rests in a conical socket in one arm of the bracket and the other in a socket in the end of a tightening-screw, j', passing through the other arm. By means ot' this screw the degree of tension required to draw off the thread from the spool is regulated.

The feeding mechanism consists of a feedingwheel, R, with a roughened surface arranged' in front of the needle and projecting above the bed, and operated in the usual manner. A bar, L, extends across the shuttle-race under the needle and the pressure-pad, and through the bar a hole is made to allow the needle to pass through. This bar carries a sliding plate, M, which can be moved forward under the neeldle'and the pressure-pad, bringing the hole in its end, which is smaller than that through the bar, opposite the hole in the bar. Thus the bed is raised opposite the feeding-wheel, and the machine adapted to sew materials varying in thickness without changing the pog, which passes through its center, so as to` bring either end of the bobbin opposite the central hole in the side ofthe shuttle, through which the thread passes, by which means the line of draft of the thread in passing through the central hole in the side of the shuttle is perpendicular to the axis ofthe bobbin, and consequently the tension required to draw ofi' the thread from all parts of the length of the bobbin at equal distances from its center is uniform, which is not the case when the bobbin does not vibrate for its entire length on either side of the hole in the shuttle through which the thread passes. In the bottom ofthe shuttle, and extending the entire length of the cavity, is a thin arched spring, h, confined at the ends to the shuttle. This arrangement of the spring tends better than any other to compensate i'or the varying length oi' leverage with. which the thread acts on the bobbin while being drawn off. \Vhen the bobbin is full and the leverage ofthe thread isgreatest, the spring is flattened along its line of contact with the thread, and acts with its greatest force to prevent the bobbin from turning. As the thread is reduced on the bobbin its leverage is gradually reduced, and the spring, expanding, be comes more arched and acts upon a less eX- tent of surface of the thread and comes in contact with the heads of the bobbin, and as the pressure of the spring on the thread diminishes its pressure onthe bobbin-heads increases, which tends to yequalize and proportion the diminishing pressure of the spring to the diminishing reduction of the length of leverage through which the thread acts on the bobbin. It will also be seen from the arrangement of this spring that there is no liability of its catching the thread and preventing the bobbin from turning or from vibrating freely on its racerod.

Having thus described my improvements in sewing-machines, what I claim therein as new, and Vdesire to secure by Letters Patent of the United States, is v l. The combination of the slide M, or its equivalent,arrangedsubstantiallyas described, with the feeding mechanism, for the purpose of adjusting the bed to the feeding mechanism for materials of various thicknesses without changing the position of the feeding mechanism.

2. In combination with the bobbin,` arranged, as described, to vibrate in the shuttle-race, the longitudinal arched pressure-spring, arranged substantially as described, for the purpose set forth.

In testimony whereof I have subscribed my name.

' J. l?. EB'ISVILER. fitnessesz EDM. F. BROWN,

M. V. B. Rlxncmrrn. 

